Soak kala vatana overnight, boil and keep aside. Heat oil in a hot pan and when the oil gets hot, add chopped onions, salt and cook them till they turn golden in colour. Add curry leaves, chopped green chillies, and mix. Once the onions turn golden in colour, add crushed garlic and chopped tomatoes and mix. Reduce the flame and add hing, turmeric powder, coriander powder, cumin powder, red chilli powder and pinch of garam masala. Add 1 cup kala vatana (soaked overnight and boiled), mix well and bring to a boil. Cover and cook on low flame for about 5-10 minutes. Add 1 tsp browned grated dry coconut, mix and just cook for a minute and switch off the flame.